Data from: Adaptation to divergent larval diets in the medfly, Ceratitis capitata

Variation in diet can influence the timing of major life history events and can drive population diversification and ultimately speciation. Proximate responses of life histories to diet have been well studied. However, there are scant experimental data on how organisms adapt to divergent diets over the longer term. We focused on this omission by testing the responses of a global pest, the Mediterranean fruitfly, to divergent selection on larval diets of different nutritional profiles. Tests conducted before and after 30 generations of nutritional selection revealed a complex interplay between the effects of novel larval dietary conditions on both plastic and evolved responses. There were proximate-only responses to the larval diet in adult male courtship and the frequency of copulation. Males on higher calorie larval diets consistently engaged in more bouts of energetic courtship. In contrast, following selection, larval development time and egg to adult survival showed evidence of evolved divergence between diet regimes. Adult body size showed evidence for adaptation, with flies being significantly heavier when reared on their ‘own’ diet. The results show the multifaceted responses of individuals to dietary selection and are important in understanding the extreme generalism exhibited by the medfly.

饮食差异可影响生物重要生命史事件的发生时序，并推动种群分化，最终导致物种形成。生命史对饮食的近因响应已得到充分研究。然而，关于生物如何在长期尺度上适应差异化饮食的实验数据却十分匮乏。针对这一研究空白，我们以全球性害虫——地中海实蝇（Mediterranean fruitfly）为研究对象，测试其在不同营养组成的幼虫饮食下的差异化选择响应。在历经30代营养选择前后开展的测试显示，新型幼虫饮食条件对表型可塑性响应与进化响应均存在影响，二者间存在复杂的交互作用。成虫雄性求偶行为与交配频率仅对幼虫饮食存在近因响应：取食高卡路里幼虫饮食的雄性，其精力旺盛的求偶频次始终更高。与之相反，经过选择后，幼虫发育时长以及卵至成虫的存活率在不同饮食处理组间表现出进化分化的特征。成虫体型也表现出适应性特征：当实蝇在其"专属"饮食条件下饲养时，体重显著更高。本研究结果揭示了个体对饮食选择的多维度响应，对于理解地中海实蝇所展现出的极强泛食性具有重要意义。